Low power W:AlOx/WOx bilayer resistive switching structure based on conductive filament formation and rupture mechanism

We report the design and fabrication of W:AlOx/WOx bilayer based resistive switching cells in a standard 0.18 mu m CMOS process with only one extra mask. The devices show excellent performance with low power consumption. Low operation voltages (SET voltage < 1.5 V, RESET voltage < 1.3 V) are achieved, and specifically, the RESET and SET currents are lower than 1 mu A. For the 0.3 mu m x 0.3 mu m active area of the cell, the current density is below 1.1 x 10(3) A/cm(2), which is much smaller than previous reported results. To reveal the resistive switching mechanism, various physical analysis techniques were employed to examine the microstructures, compositions, and chemical states. Current-voltage and capacitance-voltage electrical characterizations were carried out on these devices. Based on the physical and electrical characteristics, a conductive filament formation and rupture mechanism is proposed to explain the W:AlOx/WOx bilayer structure resistive switching phenomena. (C) 2013 AIP Publishing LLC.